GAMMA — Gamma function

Description

GAMMA(X) computes Gamma (\Gamma) of X. For positive, integer values of X the Gamma function simplifies to the factorial function \Gamma(x)=(x-1)!.

Syntax

X = GAMMA(X)

Arguments

X Shall be of type REAL and neither zero nor a negative integer.

Return value

The return value is of type REAL of the same kind as X.

Example



program test_gamma

  real :: x = 1.0

  x = gamma(x) ! returns 1.0

end program test_gamma

Specific names

Name Argument Return type Standard
GAMMA(X) REAL(4) X REAL(4) GNU Extension
DGAMMA(X) REAL(8) X REAL(8) GNU Extension

Standard

Fortran 2008 and later

Class

Elemental function

Name	Argument	Return type	Standard
`GAMMA(X)`	`REAL(4) X`	`REAL(4)`	GNU Extension
`DGAMMA(X)`	`REAL(8) X`	`REAL(8)`	GNU Extension